Bug 1734421 - Update wasm2c to support better use of 32-bit virtual space r=glandium

Differential Revision: https://phabricator.services.mozilla.com/D127727

config/external/wasm2c_sandbox_compiler/moz.yaml

@@ -9,8 +9,8 @@ origin:
   description: wasm2c fork used for rlbox sandboxing
   url: https://github.com/PLSysSec/wasm2c_sandbox_compiler
 
-  release: commit 551fd0e7d8f0349562d4402bc626a689e7ecde4f (2021-09-09T00:19:32Z).
-  revision: 551fd0e7d8f0349562d4402bc626a689e7ecde4f
+  release: commit 9670bda8add9702dcd5e785be3525c9fee340506 (2021-10-06T20:20:09Z).
+  revision: 9670bda8add9702dcd5e785be3525c9fee340506
 
   license: Apache-2.0
   license-file: LICENSE

third_party/wasm2c/wasm2c/wasm-rt-impl.c

@@ -102,13 +102,13 @@ void wasm_rt_cleanup_func_types(wasm_func_type_t** p_func_type_structs, uint32_t
 # define WASM_HEAP_RESERVE_SIZE 0x200000000ull
 # define WASM_HEAP_MAX_ALLOWED_PAGES 65536
 #elif UINTPTR_MAX == 0xffffffff
-// Reserve 16MB, aligned to 8MB, max heap is 8MB
-# define WASM_HEAP_GUARD_PAGE_ALIGNMENT 0x800000ul
+// Reserve 16MB, unaligned, max heap is 16MB
+# define WASM_HEAP_GUARD_PAGE_ALIGNMENT 0
 # define WASM_HEAP_RESERVE_SIZE 0x1000000ul
 # ifdef WASM_USE_INCREMENTAL_MOVEABLE_MEMORY_ALLOC
 #   define WASM_HEAP_MAX_ALLOWED_PAGES 65536
 # else
-#   define WASM_HEAP_MAX_ALLOWED_PAGES 128
+#   define WASM_HEAP_MAX_ALLOWED_PAGES 256
 # endif
 #else
 # error "Unknown pointer size"

third_party/wasm2c/wasm2c/wasm-rt-os-unix.c

@@ -127,8 +127,9 @@ void* os_mmap_aligned(void* addr,
   }
 
   // Round up the next address that has addr % alignment = 0
+  const size_t alignment_corrected = alignment == 0? 1 : alignment;
   uintptr_t aligned_nonoffset =
-      (unaligned + (alignment - 1)) & ~(alignment - 1);
+      (unaligned + (alignment_corrected - 1)) & ~(alignment_corrected - 1);
 
   // Currently offset 0 is aligned according to alignment
   // Alignment needs to be enforced at the given offset
@@ -142,7 +143,7 @@ void* os_mmap_aligned(void* addr,
   // Sanity check
   if (aligned < unaligned ||
       (aligned + (requested_length - 1)) > (unaligned + (padded_length - 1)) ||
-      (aligned + alignment_offset) % alignment != 0) {
+      (aligned + alignment_offset) % alignment_corrected != 0) {
     VERBOSE_LOG("os_mmap_aligned: sanity check fail. aligned: %p\n", (void*) aligned);
     os_munmap((void*)unaligned, padded_length);
     return NULL;

third_party/wasm2c/wasm2c/wasm-rt-os-win.c

@@ -175,8 +175,9 @@ void* os_mmap_aligned(void* addr,
     }
 
     // Round up the next address that has addr % alignment = 0
+    const size_t alignment_corrected = alignment == 0? 1 : alignment;
     uintptr_t aligned_nonoffset =
-        (unaligned + (alignment - 1)) & ~(alignment - 1);
+        (unaligned + (alignment_corrected - 1)) & ~(alignment_corrected - 1);
 
     // Currently offset 0 is aligned according to alignment
     // Alignment needs to be enforced at the given offset
@@ -195,7 +196,7 @@ void* os_mmap_aligned(void* addr,
     if (aligned < unaligned ||
         (aligned + (requested_length - 1)) >
             (unaligned + (padded_length - 1)) ||
-        (aligned + alignment_offset) % alignment != 0) {
+        (aligned + alignment_offset) % alignment_corrected != 0) {
       VERBOSE_LOG("os_mmap_aligned: sanity check fail. aligned: %p\n", (void*) aligned);
       os_munmap((void*)unaligned, padded_length);
       return NULL;